Something broke in my honda gxh50

finding0

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Dec 18, 2016
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So I was pushing the motor a little harder than I should have. Suddenly while going down a hill I lost speed and her a snap. The motor shut off. Now when I pull the recoil starter i get no resistance and it wont start. What did I break and can I fix it? Thank you
 


LewieBike

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May 21, 2014
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I hate to be the one to say it, but I think you may have to have the engine's case opened because this sounds like a broken connecting rod.
 

finding0

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Dec 18, 2016
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That is what I was thinking. Do i need special tools for this? Im always willing to learn a new skill.
 

The_Aleman

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May 2, 2007
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Worst-case, the whole con-rod is busted. Best-case, the bolts on the big end gave out and there's no damage. That happened to my brother's GXH50, although the oil dipper on the end of the rod cap is one of the first things to break at high RPM.

No special tools are needed to fix one of these, although a real Honda con rod costs twice as much as a clone (Huasheng) con rod, which is pretty much the same thing. They've been known to fail on either engine at RPMs beyond 8500, doesn't matter that the Honda is a Honda.

The hardest part is messing with the cam and actuator assembly with the tiny pushrods, but it aint real hard and the GXH50 shop manual is readily available online. You can also Google Image some other pics and perhaps find YT videos on a rebuild if you want maximum guidance!


GXH50timing.jpg
 

LR Jerry

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Mar 14, 2011
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The highest recommended rpm for the Honda GXH 50 is 7500. The max horsepower is at 7000 rpm. You should get a hour counter/tachometer. They're simple to install. The wire wraps around the spark plug wire. The hour counter is great too. That way you know exactly when to change the oil and clean the air filter.

For the Honda GXH50 clean the air filter every 10 hours of use. Change the oil every 25 hours of use. I use a small vacuum pump to change the oil. Good preventive maintenance and not over revving or over straining the engine will help these engines last for years.

If you're using a shift kit be in a gear where you stay very close to 7000 RPM using max throttle. If you're going over the general area of 7000 rpm at max throttle shift to a higher gear. If you can't obtain close to 7000 rpm at max throttle shift to a lower gear. Trying to run in too high of a gear puts strain on the engine and can be just as bad as over revving.
 
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mark20

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Sep 26, 2018
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So I was pushing the motor a little harder than I should have. Suddenly while going down a hill I lost speed and her a snap. The motor shut off. Now when I pull the recoil starter i get no resistance and it wont start. What did I break and can I fix it? Thank you
sounds like a broken rod as most people stated.
but you have to open it up to see what it really is.
did you change the spark plug to a different one that was, non matched, different heat range? i could be that caused it to melt the electrode and blew a hole in the piston
remove the spark plug and if see if the piston is moving up and down (if it is your rod is good)
if not, its a rod.
if you do, remove the head and see if theres any signs of damage
then open up the crank case and see if theres any signs (drain the oil first, that can tell you a lot, but for simplicity, grey means theirs metal fragments, aka bad.)
and look for damage!

hope this helps, and good luck!
 

LewieBike

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May 21, 2014
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491
It's funny that Honda elected to go to a splash lubed plain bushing bearings on the 50 when the GX series 25/31 and 35 all have ball and needle bearings on the connecting and crankshaft. I've never seen a sub 49 cc Honda GX that was trashed from overrevving.
 
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